Precision alloys are metal materials with special physical properties such as magnetism, electrical properties, and thermal properties. Most precision alloys are based on ferrous metals, and only a few are based on non-ferrous metals. Generally, it includes a magnetic alloy, an elastic alloy, an expanded alloy, a hot bimetal, an electric alloy, a hydrogen storage alloy, a shape memory alloy, a magnetostrictive alloy, etc.